The goal of research at Hospital for Special Surgery is to identify the mechanisms underlying musculoskeletal, infammatory and autoimmune diseases and to develop effective approaches for prevention, diagnosis and treatment of these disorders. One out of every seven Americans reports having a musculoskeletal impairment, the most common cause of severe long-term pain and physical disability across the globe; and autoimmune diseases, which affect women at a higher rate than men, are the fourth largest cause of disability among women in the US and among the top ten causes of death. Interactions between specific molecular species in living cells and their subcellular localizations are critical in understanding the mechanisms of autoimmune, inflammatory and musculoskeletal diseases, the research focus of the Hospital for Special Surgery. Confocal microscopy provides a significant tool for investigators to visualize cellular processes that play roles in the underlying mechanisms of these diseases and to identify new targets for therapeutic interventions. Optical resolution in conventional fluorescent microscopy is severely affected by stray light entering the focal plane. In a conventional wide-field optical epi-fluorescence microscope, secondary fluorescence emitted by the specimen often occurs through the excited volume and obscures resolution of features that lie in the objective focal plane. The problem is further compounded by thicker specimens (greater than 2 micrometers), which usually exhibit such a high degree of fluorescence emission that most of the one detail is lost. Confocal microscopy provides not only high resolution images from specimens prepared for conventional fluorescence microscopy, but also allows quantitative fluorescence measurements. The requested system offers several advantages over conventional wide-field optical microscopy, including the ability to control depth of eld, elimination of reduction of background information away from the focal plane (that leads to image degradation), and the capability to collect serial optical sections from thick specimens. [unreadable] [unreadable] [unreadable]